diff --git a/src/chainparams.cpp b/src/chainparams.cpp
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -131,6 +131,9 @@
         // Nov 15, 2018 hard fork
         consensus.magneticAnomalyActivationTime = 1542300000;
 
+        // May 15, 2019 hard fork
+        consensus.greatWallActivationTime = 1557921600;
+
         /**
          * The message start string is designed to be unlikely to occur in
          * normal data. The characters are rarely used upper ASCII, not valid as
@@ -300,6 +303,9 @@
         // Nov 15, 2018 hard fork
         consensus.magneticAnomalyActivationTime = 1542300000;
 
+        // May 15, 2019 hard fork
+        consensus.greatWallActivationTime = 1557921600;
+
         diskMagic[0] = 0x0b;
         diskMagic[1] = 0x11;
         diskMagic[2] = 0x09;
@@ -423,6 +429,9 @@
         // Nov 15, 2018 hard fork
         consensus.magneticAnomalyActivationTime = 1542300000;
 
+        // May 15, 2019 hard fork
+        consensus.greatWallActivationTime = 1557921600;
+
         diskMagic[0] = 0xfa;
         diskMagic[1] = 0xbf;
         diskMagic[2] = 0xb5;
diff --git a/src/consensus/params.h b/src/consensus/params.h
--- a/src/consensus/params.h
+++ b/src/consensus/params.h
@@ -56,6 +56,8 @@
     int daaHeight;
     /** Unix time used for MTP activation of Nov 15 2018, hardfork */
     int magneticAnomalyActivationTime;
+    /** Unix time used for MTP activation of May 15 2019, hardfork */
+    int greatWallActivationTime;
     /**
      * Minimum blocks including miner confirmation of the total of 2016 blocks
      * in a retargeting period, (nPowTargetTimespan / nPowTargetSpacing) which
diff --git a/src/validation.cpp b/src/validation.cpp
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -599,7 +599,7 @@
     return nMedianTimePast >= gArgs.GetArg("-replayprotectionactivationtime",
                                            config.GetChainParams()
                                                .GetConsensus()
-                                               .magneticAnomalyActivationTime);
+                                               .greatWallActivationTime);
 }
 
 static bool IsReplayProtectionEnabled(const Config &config,